Braun tube



June 8, 1937. M. voN ARDENNE 2,083,209

l BRAUN TUBE Filed April 17. 1953 .PEFLEcr/A/G MEA/V5 /Uvenforw PatentedJune 8, 1937 y UNITED STATES PATENT OFFICE Application April 17, 1933,Serial No. 666,555 Y In Germany March 27, V1931 17 Claims.

'Ihe invention relates to a reception device for television with Brauntubes.

Improvements in the quality of the image in the case of televisionreceiving arrangements employing Braun tubes operating with deiiectioncontrol are obtained byfthe use of after-concentration cylinders.

However, as extensive investigations have shown, a certain distortion ofthe image is also 10 caused by these improved Braun tubes.

Now the further object of the invention is by an arrangement, in whichall distortions are wholly eliminated. rBy reason of the deilectingplate, or pairs of deiiecting plates, the cathode ray is imparted adirection, which deviates from the central one, and which could also notbe entirely compensated by the after-concentration cylinder. It wascertainly possible with the assistance'of the after-concentrationcylinder to obtain a considerable improvement in the image, but this,`as later experiments have shown, is based solely on the fact that theray, which is caused to diverge, particularly by reason of thedeflection, is again more sharply concentrated,V

whereby certainly a partial return to the center line is also obtained.

According now to the invention, there is employed for returning the rayto the axis of the tube a second deecting plate, or pair of deectingplates, which preferably operate in countercadence to the deecting platecontrolling the `intensity of light. By reason of thiscounterplate'principle it is accomplished that the ray after leaving thevicinity of the second plate of the' returning plate proceeds co-axiallyto the tube, so that in this case an after-concentration cylinder is notabsolutely essential. This arrangement Will be described more fully inconjunction with a possible Aform of embodiment as 40 illustrated inthey appended drawing', the single gure of which shows a Braun tube andcertain connecting means associated therewith, both designed inaccordancewith thi-s invention.

In the figure 56 is the cathode, 51 the Wehnelt cylinder, 58 thedeflecting 'plate controlling the intensity of the ray, and 59 theanode. The deilecting plate 5 again returns the ray to the center axisof the tube, where the same, if necessary, may'again be more greatlyconcentrated by an after-concentration cylinder 6| and thereupon deectedby means of the deiiecting plates systems 62 and 63 in two directionsfor scanning the fluorescent screen 64 on which the image to betransmitted appears.

According to the additional subject matter of (Cl. Z50-27.5)

the invention, the distance of the deecting plate 58 and also that ofthe returning plate 5 from the axis of the tube is so chosen that thesame is large as compared with the diameter of the ray at the point ofcontrol, in order to avoid dis 5 tortions. 'I'hese distortions are basedto a large extent on the space charge fog which develops between thisplate and the ray, and which prevents a. linear control characteristic.

Since the iniluence of the two deilecting andV 10 returning plates, orpairs of plates, on the cathode ray varies in consequence of the variedspeed of the electrons arising from the intermediately located anode,the D. C. potential bias of the returning plate 5 is adjusted separatelyfrom that 15 of the plate 58. For the purpose of dynamic control the twoplates 58 and 5 may be connected in simple fashion by means of acondenser 12. 'Ihe suitable biasing potential for the plate 5 may beobtained in simple manner by connecting thiswith the anode 59 throughthe medium of a 20 regulable resistance ll.

Although, as stated above, it is not absolutely essential to employ theafter-concentration cylinder 6| when making use of the counter-plateprinciple, the combination of after-concentration cylinder andcounter-plate principle nevertheless results in very considerableimprovements in the quality of the image, as it is possible to eliminatenot only the image-point displacement by the plate 5 but also the lackof sharpness by the afterconcentration cylinder 6|.

In 'order to also obtain from a dynamic standpoint a particularly lineadjustment of thecoaxialnature of the ray, there is provided, accordingto the invention, outside of the tube a displaceable plate 66, which issituated parallel to the returning plate 5 and is connected with thesame. The displacement of this plate may be performed in desireddirection, and permits 40 ot extremely ne subsequent adjustment of thereturn deilection of the ray. This plate is connected with the returningplate.

As shown in the single gure of the drawing, further plates 61, 69, and10, hereinafter termed 45 counter-plates, may be provided so that pairsof plates are formed, one comprising the plates 58 and 61, another onecomprising the plates 5 and 69, and a third one comprising the plates 66and 10, the relative positions of the two plates 50 of each of thementioned pairs being symmetrical with respect to the tube axis. Byusing such pairs instead of the single plates 58, 5 or 66 respectively,the homogeneity of the deflecting fields is increased, the eii'ect ofwhich improvement is 55 particularly favourable as regards the counterplate 'I0 of the plate 86. 'I'his last mentioned counter plate ispreferably earthed with respect to alternating current, but suppliedwith a D. C. potential for the purpose of preventing a change in tnespeed of the cathode ray.

To preclude detrimental influence on the part of the controlling plates58 and 5 on the concentration cylinders 51 and 6I the distance betweenthe initial-deflection plates,` or pairs of plates and the concentrationcylinders is, according to the invention, made of suilicient extent. Thecomplete control oi' the television arrangement as described occurs inthe known manner by passing the light intensity potential to theinitialdeection plate 58 and the image or line potential to the pairs ofplates 62 and 63.

I claim:

1. A Braun tube comprising a cathode, deflecting means and a fluorescentscreen, a concentrating cylinder arranged near said cathode, onedeecting plate arranged at one side of the tube-axis, a perforatedshutter mounted between said defiecting plate and said screen, a furtherdeflecting plate arranged at the opposite side of the tube axis, anadjustable deflecting plate arranged outside said tube in parallel tosaid further deflecting plate and connected thereto, and a concentratingcylinder arranged between said further deflecting plate and saiddeflecting means.

2. A Braun tube comprising a cathode, a perforated anode and afluorescent screen, means for defiecting the cathode ray in onedirection and means for deecting the ray in a direction perpendicular tothe rst said one for scanning v said screen, said deflecting means beingarranged between said anode and said screen, one deflecting platearranged at one side of the .tube axis between said cathode and saidanode, said deecting plate being adapted to be supplied with a controlvoltage, and afurther deecting plate arranged at the opposite side ofthe tube axis between said anode and said deecting means, said furtherdeflecting plate being adapted to be supplied with a redeflectlngvoltage.

3. A Braun tube comprising a cathode, a perforated anode and afluorescent screen, means .for deflecting the cathode ray in onedirection and means for deecting the ray in a direction perpendicular tothe iirst said one for scanning said screen, said deiecting means beingarranged between said anode and said screen, one deflecting platearranged at one side of the tube axis between said cathode and saidanode, said defiecting plate being adapted to be supplied with a controlvoltage, a further deecting plate ar ranged at the opposite side of thetube axis between said anode and said deflecting means, said furtherdeflecting plate being adapted to be suppliedl with a redeiiectingvoltage, and concentrating means arranged between said furtherdefiecting plate and said deecting means.

4. A Braun tube comprising a cathode, a perforated anode and a uorescentscreen, means for deiiecting the cathode ray in one direction and meansfor deflecting the ray in a direction perpendicular to the rst said onefor scanning said screen, said deflecting means being arranged betweensaid anode and said screen, one deecting plate arranged at one side ofthe tube axis between said cathode and said anode, said defiecting platebeing adapted to be supplied with a control voltage, a furtherdeflecting plate arranged at the opposite side of the tube axis betweensaid anode and said deiiecting means, said further deecting plate beingadapted to be supplied with a redeecting voltage, and a concentratingcylinder arranged between said further deiecting plate and saiddeflecting means.

5. A Braun tube comprising a cathode, a perforated anode and afluorescent screen, means for deflecting the cathode ray in onedirection and means for deflecting the ray in a direction perpendicularto the first said one for scanning said screen, said deflecting meansbeing arranged between said anode and said screen, one deecting platearranged at one side of the tube axis between said cathode and saidanode, said deecting plate being adapted to be supplied with a controlvoltage, and a further deflecting plate arranged at the opposite side ofthe tube axis between said anode and said deflecting means, said furtherdeflecting plate being adapted to be supplied with a redeflectingvoltage comprising a variable direct current bias.

6. A Braun tube comprising a cathode, a perforated anode and afluorescent screen, means for defiecting the cathode ray in onedirection and means for deflecting the ray in a direction perpendicularto the rst said one for scanning said screen, said deflecting meansbeing arranged between said anode and said screen, one deecting platearranged at one side of the tube axis between said cathode and saidanode, said dei-lectlng plate being adapted to be supplied with acontrol voltage, a further deflecting plate arranged at the oppositeside of the tube axis between said anode and said deilecting means, saidfurther deflecting plate being adapted to be supplied with aredeflecting voltage, and a variable resistance connecting said furtherdefiecting plate with said anode.

7. A Braun tube comprising a cathode, a perforated anode and afluorescent screen, means for deecting the cathode ray in one directionand means for deecting the ray in a direction perpendicular to the firstsaid one for scanning said screen, said deecting means being arrangedbetween said anode and said screen, one deflecting plate arranged at oneside of the tube axis between said cathode and said anode, saiddeflecting plate being adapted to be supplied with a control voltage, afurther deflecting plate arranged at the opposite side of the tube axisbetween said anode and said deecting means, and connecting meanscomprising a condenser connecting the two said deecting plates.V

8. A Braun tube comprisingan envelope, a cathode, a perforated anode anda uorescent screen, means for defiecting the cathode ray in onedirection and means for deecting the ray in a direction perpendicular tothe lrst said one for scanning said screen, said deilecting means beingarranged between said anode and Vsaid screen, one deecting platearranged at one side of the tube axis between said cathode and saidanode, said deflecting plate being adapted to be supplied with a controlvoltage, a further deecting plate arranged at the opposite side of thetube axis between said anode and said defiectingmeans, said furtherdeflecting plate being adapted to be supplied with a redeecting voltage,and a third deecting plate movably mounted outside said envelope andalso adapted to be supplied with a redefiecting voltage for neadjustment of the redeection.

9. A Braun tube comprising a cathode, a perforated anode and a uorescentscreen, means for deiiecting the cathode ray in one direction and meansfor deiiecting the ray in a direction perpendicular to the first saidone for scanning said screen, said deiiecting means being arrangedbetween said anode and said screen, one pair of defiecting platesarranged between said anode and said cathode, said pair of deiiectingplates being adapted to be supplied with a control voltage, and afurther pair of deecting plates arranged between said anode and saiddeecting means, said further pair of defiecting plates being adapted tobe supplied with a redeiiecting voltage.

10. A Braun tube comprising a cathode, a perforated anode and aiiuorescent screen, means for deecting the cathode ray in one directionand means for deiiectingthe ray in a direction perpendicular to the rstsaid one, for scanning said screen, said deiiecting means being arrangedbetween said anode and said screen, one pair of defleeting platesyarranged between said cathode and said anode, said pair of deectingplates being adapted to be supplied with a control voltage, a furtherpair of defiecting plates arranged between said anode and saiddeiiecting means, said further pair of defiecting plates being adaptedto be supplied with a redeiiecting voltage, and concentrating meansarranged between said further pair of deecting plates and saiddefiecting means.

11. A Braun tube comprising a cathode, a perforated anode and aiiuorescent screen, means for deiiecting the cathode ray in onedirection and means for defiecting the ray in a directionperpendicular'to the iirst said one for scanning said screen, saiddefiecting means being arranged between said anode and said screen, onepair of deecting plates arranged between said cathode and said'anode,said pair of deiiecting plates being adapted to be supplied with acontrol voltage, a further pair of defiecting plates arranged betweensaid anode and said defiecting means, said further pair of defiectingplates being adapted to be supplied with a redeflecting voltage, and aconcentrating cylinder arranged between said further pair of dei'lectingplates and said defiecting means.

12. A Braun tube comprising a cathode, a perforated anode and afluorescent screen, means for defiecting the cathode ray in onedirection and means for deiiecting the ray in a direction perpendicularto the rst said one for scanning said screen, said deecting means beingarranged between said anode and said screen, one pair of deilectingplates arranged between said cathode and said anode, said pair ofdefiecting plates being adapted to be supplied with a control voltage,and a further pair of defiecting plates arranged between said anode andsaid defiecting means, said further pair of deiiecting plates beingadapted to be supplied with a redeiiecting voltage comprising a variabledirect current bias.

13. A Braun tube comprising a cathode, a perforated anode and afluorescent screen, means for defiecting the cathode ray in onedirection and means for defiecting the ray in a direction perpendicularto the first said one for scanning said screen, said defiecting meansbeing arranged between said anode and said screen, one pair of deectingplates arranged between said cathode and said anode. said pair ofdefiecting plates being adapted to be supplied with a control voltage, afurther pair of defiecting plates arranged between said anode and saiddeflecting means, said further pair of defiecting plates being adaptedto be supplied with a redefiecting voltage, and a variable resistanceconnecting said further pair of defiecting plates arranged between saidcathode c and said anode, said pair of deecting plates being adapted tobe supplied with a control voltage, a further pair of defiecting platesarranged between said anode and said defiecting means, and connectingmeans comprising a condenser connecting the two said pairs of deectingplates.

` 15. A Braun tube comprising an envelope, a cathode, a perforated anodeand a fiuorescent screen, means for deflecting the cathode ray in onedirection and means for defiecting the ray in a direction perpendicularto the rst said one for scanning said screen, said deiiecting meansbeing arranged between said anode and said screen, one pair ofdefiecting plates arranged between said cathode and said anode, saidpair of deecting plates being adapted to be supplied with a controlvoltage, a further pair of defiecting plates arranged between said anodeand said defiecting means, said further pair of deecting plates beingadapted to be supplied with a redeectng voltage, and a third pair ofdefiecting plates movably mounted outside said envelope and alsofadapted to be supplied with a redeflecting voltage for fine adjustmentof the redeiiection.

16. A Braun tube comprising a cathode, an anode, a picture receivingscreen, said anode being mounted between said cathode and said screen,electrodes for defiecting the cathode ray in one direction and means fordeiiecting the cathode ray in a direction perpendicular to the iirstsaid onefor scanning said screen, said electrodes and said means fordeiiecting the cathode ray being mounted between said anode and saidscreen, an electrode for concentrating the cathode ray mounted near saidcathode, means for further concentrating the cathode ray comprising anelectrode mounted between said anode and said defiecting electrodes,said electrode mounted between said anode and said defiecting electrodesbeing spaced far enough from said defiecting electrodes for avoiding adisturbing iniiuence upon one another.

1'1. A Braun tube comprising a cathode, an anode, a picture receivingscreen, said anode being mounted between said cathode and said screen,electrodes for defiecting the cathode ray in one direction and means fordefiecting the cathode ray in a direction perpendicular to the firstsaid one for scanning said screen, said electrodes and said means fordeecting the cathode ray being mounted between said anode and saidscreen, an electrode for concentrating the cathode ray mounted near saidcathode, means for further concentrating the cathode ray comprising acylindrical electrode mounted between said anode and said defiectingelectrodes, said cylindrical electrode being spaced far enough from saiddeilect ing electrodes for avoiding a disturbing iniiuence upon oneanother.

MANFRED VON ARDENNE.

